The hydrocephaly treatment devices currently in use comprise an intracranial catheter connected to a tube which is fitted with a valve and which enables the flow of cephalo-rachidian liquid to be diverted to one or more cavities in the organism capable of absorbing said liquid. As a general rule the cavity used is the peritoneum or the right auricle of the heart.
The valves used over the last 20 years have been based on the principle of maintaining a constant intracranial pressure regardless of the flow rate. Various types of non-return valve opening at a threshold pressure have thus been used, sometimes in conjunction with anti-siphon valves.
These devices do not give entire satisfaction: they clip all variations in intracranial pressure regardless of whether they are abnormal or normal (e.g. when making an effort, or during paradoxical sleep); furthermore, they cope poorly with the suction effects due to sudden pressure drops induced in the tube when the patient rises from a lying position to a sitting position, or from a sitting position to a standing position.
The present invention provides a device which goes against the principle of maintaining the intracranial pressure constant.